High-efficiency GaN-based LED with patterned SiO2 current blocking layer deposited on patterned ITO

GaN-based blue light-emitting diodes (LEDs) with patterned SiO₂ current blocking layer (CBL) deposited on patterned indium-tin oxide (ITO) transparent conductive layer has been proposed and performed. The patterned SiO₂ layer was inserted between ITO and p-/n-electrodes, serving as both CBL and passivation layer. The results showed that the proposed single patterned SiO₂ CBL can significantly improve the current spreading and light emission intensity of the fabricated LEDs. Additionally, the ITO with periodic circular patterns underneath p-electrode was formed to enhance scattering events of light emanated from InGaN/GaN active emitting region, leading to a reduced light absorption by opaque p-electrode and improved light extraction efficiency (LEE). As a result, at 200 mA, the external quantum efficiency (EQE) of the LED with patterned SiO₂ CBL deposited on patterned ITO was 13.8% higher than that of conventional LED.